The user interface
Screens, navigation, forms and device interactions make up the part people use. A working design also needs loading, empty, error and offline states where those apply.
A project planning guide by AppCodie
App code: what to build, own and hand over
App code is the source code behind an application: the instructions developers write to make its screens, features and connections work. Before commissioning an app, understand what your project includes and what you will need to run it after launch.
What is included in app source code?
Data and business rules
Accounts, permissions, calculations and saved information may live partly on the device and partly on a server. An app repository does not necessarily include its backend or administration tools.
Build and test setup
Dependencies, configuration examples, tests and build instructions help another developer reproduce a release. Source files alone are not the same as an installable app or a running service.
Example: an appointment booking app
The mobile screen collects a requested time. A server checks availability and saves the booking. A staff dashboard manages appointments, while a notification service sends reminders. Agree which of these parts are included before comparing estimates for the app.
Choose the platform around your users
Start with the devices your customers use, the features they need and the team that will maintain the product. The smallest useful first release is often easier to estimate than a list of every possible feature.
- iPhone and iPad: an iOS project can focus on Apple devices and their platform capabilities. Define supported devices, permissions and release requirements in the brief.
- iOS and Android: consider whether a shared approach such as Flutter fits the required experience. Shared code still needs testing on each platform, and some integrations require platform-specific work.
- A browser-based app: a web application may suit workflows that users need to access by a link. Check device features, connectivity and offline needs before choosing it over a mobile app.
For an existing product, review the current repository, dependencies and build process before deciding whether to extend or replace it. A screenshot or app-store listing cannot show the condition of the underlying code.
A practical app code handover checklist
Use these questions when agreeing project scope and accepting delivery. Record the answers in the project agreement; ownership and ongoing support should not be assumed.
- Repositories and ownership. Which mobile, backend and dashboard repositories will you receive? Clarify ownership of custom work, access permissions and any reusable or third-party components.
- A reproducible build. Ask for the required tool versions, dependency setup, configuration template and build instructions. Have the receiving developer build the agreed release from a clean checkout.
- Accounts and credentials. Identify who controls hosting, app-store accounts, signing materials, databases and external services. Transfer access securely and document which credentials need rotation.
- Data and integrations. Include database setup or migrations, API documentation and the services the app relies on. Explain backup and restore responsibilities, recurring fees and account limits.
- Testing and known issues. Agree the supported devices and essential user journeys. Record test results, known limitations and acceptance criteria so both teams can assess the same release.
- Release and maintenance. Document deployment, rollback and monitoring steps. Define who handles defects, operating-system updates, dependency upgrades and future features after handover.
Plan your app with AppCodie
AppCodie builds websites, mobile apps and custom software. Share your intended users, target platforms, essential workflows and existing systems so the team can discuss a suitable development scope.
If you already have source code, describe its technology, current build status and the changes you need. Ownership, repository access, third-party licenses and maintenance responsibilities are agreed as part of the project scope.
Discuss your app project